The authors found no differences in results between men and women, but they cautioned that their study was not adequately powered to test for interaction by sex. Researchers found the key is frequency - exercise needs to be done four or five times a week in order to reverse heart damage - anything less wasn't enough.
"The "sweet spot" in life to get off the couch and start exercising is in late-middle age, when the heart still has plasticity", lead study author Benjamin Levine, a cardiologist from the University of Texas Southwestern Medical Center, said in a release. "That's when heart failure develops", he said.
That dose is varied stints of mostly aerobic exercise - what you'd label "cardio" - performed four to five times a week, at moderate to high intensities, for at least a two-year period.
Exercise can reverse damage to sedentary, aging hearts and help prevent risk of future heart failure - if it's enough exercise, and if it's begun in time, according to a new study by cardiologists at UT Southwestern and Texas Health Resources.
What wasn't known is how late in life a person can act to reduce that risk, and how much effort this would require.
Combining yoga with aerobic exercise can also benefit hearts. Participants were all healthy but sedentary at the start of the study; individuals were excluded if they exercised for more than 30 minutes at least three times per week.
The researchers analyzed the hearts of 53 adults ages 45-64 who were healthy but sedentary at the start of the study, meaning they tended to sit most of the time. In addition to endurance training, the exercise group was prescribed two strength training sessions per week, mostly focused on entire body and core training.
One was that volunteers were willing and able to participate in an intensive exercise regimen, which may not be the case for the general adult population. Roughly half of the participants (28 people) did an aerobic exercise program that included at least one day per week of a high-intensity interval workout.More news: Xbox One 'Do not Disturb' feature now in testing
Another session, lasting up to an hour, is a moderate-intensity activity that you'd barely think of as exercise - something like a brisk-paced walk, a game of tennis, a bike ride, or a similar activity you enjoy.
The regimen also included two recovery days that followed interval training, consisting of 20 to 30 minutes of walking or light aerobic activity. "You can work out hard and then recover, and it feels really good".
Study participants built up to those levels, beginning with three, 30-minute, moderate exercise sessions for the first 3 months and peaked at 10 months when two high-intensity aerobic intervals were added.
The study's participants were divided into two groups, with one following an aerobic exercise routine that progressed in intensity over the two years and another doing yoga, balance training and weight training three times a week, also for two years. Try to shake hand with a healthy lifestyle that can bring many positive things to you. "We've got the "sweet spot" in age - late middle age", Levine said.
Even though the participants were on their own for most of those sessions, they got a lot of guidance about what to do, Levine said.
"It's my prescription for life", Levine said. "You need to find ways to incorporate it into your daily activities". It has helped many middle-aged people to tune up their old hearts.
According to Levine, committing to this dose of exercise is nearly as effective at preventing heart damage caused by a sedentary lifestyle as the extreme regimens of elite athletes.
The findings at the end of the study revealed that those who had exercised showed an 18 per cent improvement in their maximum oxygen intake during exercise and a more than 25 per cent improvement in compliance, or elasticity, of the left ventricular muscle of the heart.